1. Field of the Invention
The present invention relates to an electron amplification plate and, more particularly, to an electron amplification plate used in a field emission display device.
2. Description of Related Art
Many contemporary apparatuses, such as a computer, a television, a mobile phone, a personal digital assistant, or a vehicle information system, show signals through controlling a display device. Flat panel display devices, such as a liquid crystal display device, an organic light emitting display device, and a field emission display devices are the preferred display devices due to their low weight, small volume, and little effect to people's health. Among these flat panel display devices, the field emission display device (FED) has the advantages of good picture quality, high yield, short response time, easy-coordinating display characteristics, brightness of over 100 ftL, low weight, minimal thickness, large color-temperature range, good operation efficiency, and wide viewing angle. Compared with the field emission display device, the viewing angle, the range of operation temperature, and the response speed of the conventional liquid crystal display device are small. Besides, the field emission display device performs with high brightness even under sunlight because it is provided with a phosphor layer and it emits light without need for an additional back light module. Therefore, the field emission display device is considered to be the display device, which has ability to compete with or replace the liquid crystal display device.
Under a vacuum circumstance lower than 10−6 torr, the field emission display device can generate electrons from the emitters on the cathode electrode while supplying an electric field. The electrons emitted from the emitters are subsequently attracted by the positive voltage applied to the anode electrode to thereby impact the phosphor powder and illuminate at the same time. It is known that the electric field supplied to the cathode electrode affects a quantity of the electrons emitted from the emitters. In other words, the larger the electric field supply to the cathode electrode, the more electrons are emitted from the emitters. However, the gate electrode disposed around the emitters has a shape of a ring. As a result, the electric field is not uniform because the electric field is formed in the peripheries of the emitters by the difference in voltage between gate electrode and cathode electrode. For this reason, the dispersion of the electrons emitted from the emitters is presented with a ring shape, which results in disproportionate image brightness and decreases the picture quality of the field emission display device.
Therefore, it is desirable to provide an improved field emission display device to mitigate and/or obviate the aforementioned problems.